CEL-SCI Corp (VIENNA, Virginia), a clinical stage biopharmaceutical company, announced the discovery of a novel peptide vaccine for the treatment of rheumatoid arthritis (RA). The vaccine, CEL-2000, was tested in an animal model of RA and was compared with Enbrel^®. The tests showed that CEL-2000 is equivalent or possibly superior to Enbrel in slowing disease progression and lessening symptoms in mice. In addition, the vaccine has the potential to require fewer and smaller doses, to be less toxic and more disease specific, as well as much less invasive. The company also believes that the vaccine could be attractive to patients who are not able to take or respond to Enbrel, Remicade^®, or Humira^®. It discovered CEL-2000 as a result of ongoing research and development activities with its LEAPS™ (Ligand Epitope Antigen Presentation System) technology. CEL-2000 is thought to work by reducing or stopping the immune system from attacking the patient’s joints.

To induce the disease, mice were injected with collagen on days 0 and 21. Once the mice reached a significant and uniform disease state, therapy with Enbrel and CEL-2000 was initiated.  CEL-2000 was administered only twice and Enbrel was administered every other day over the entire 28-day study period. The mice were scored at least three times a week for arthritis index, foot pad swelling, and weekly weight change. Periodically, sera were collected for assessment of parameters relating to immune status. No significant weight changes were observed.  

Mice administered two doses of CEL-2000, given either on days 0 and 7 or on days 0 and 14, showed a statistically significant decrease in disease progression and were less symptomatic than the mice given Enbrel every other day through day 28. Expected serological changes were observed for both anti-LEAPS vaccines and collagen in these groups.

LEAPS is a novel T-cell modulation platform technology that enables CEL-SCI to design and synthesize proprietary immunogens. Any disease for which an antigenic sequence has been identified such as infectious, parasitic, malignant, or autoimmune diseases and allergies, are potential therapeutic or preventive sites for the application of the technology. LEAPS constructs containing the antigenic disease epitope linked to a T-cell binding ligand can be manufactured by peptide synthesis or by covalently linking the two peptides thereby mimicking cell/cell interactions on the T-cell surface. CEL-SCI is able to direct the outcome of the immune response toward the development of T-cell function primarily with effector T-cell functions (T-lymphocyte; helper/effector T-lymphocyte, type 1 or 2, cytotoxic or suppressor).